A Robust Network Covert Channel Algorithm Based on Spread Coding

In order to solve the problem that the covert timing channel works unstable in the noisy network, a method of designing robust covert channel is proposed. The method uses the interval time of network packets to transfer information, the sender codes covert information using hash spreading spectrum, and the receiver forecasts the channel noise and eliminates it. In order to solve the contradictory relationship between transmission rate and robustness, the strategy of maximizing robustness under fixed transmission rate is proposed. The experimental environment of this covert channel is constructed and several experiments are conducted. The results show that the ability to resist noise is increased about by 20%, compared with other methods on the same problem.